1. Field of the Invention
The present invention relates to a data communication device, an image-forming device such as a copy machine or a facsimile composite device, an image-forming-device management system composed of the data communication device and the image-forming device, and a method of controlling power supply in the image-forming-device management system.
2. Description of the Related Art
An image-forming-device management system enables each image-forming device installed in a large number of customer offices and the like to connect to a central management device installed in a service center by using a data communication device and a communication line such as a public line or an exclusive line. This image-forming device is defined as a copy machine, a printer, a facsimile device, or the like. Additionally, the central management device carries out remote management of the image-forming device through the communication line and the data communication device (a line adaptor). Such an image-forming-device management system is generally known.
In the above-described image-forming-device management system, the image-forming device transmits data to the data communication device periodically, for instance, at a certain time every day. Alternatively, the image-forming device transmits the data to the data communication device, in response to a data-transmission requesting signal received from the data communication device. This data is related to the image-forming device, and is, for instance, data that indicates a device status including log information such as a total number of formed images (a total counter value) and a surface temperature (a fixing temperature) of a fixing roller inside a fixing unit.
The data communication device stores the data received from the image-forming device in a memory. The data communication device, then, transmits the data stored in the memory to the central management device by calling out spontaneously and periodically, for instance, on a fixed date and time of every month. Alternatively, the data communication device transmits the data stored in the memory to the central management device, in response to a call signal, in fact, a data-transmission requesting signal included in each signal received continuously after the call signal, which corresponds to a call out made by the central management device, and is supplied through the communication line.
Additionally, the data communication device obtains data related to the image-forming device by transmitting the data-transmission requesting signal to the image-forming device in accordance with the call signal that corresponds to the call out made by the central management device, and is received through the communication line, and, then, transmits the data to the central management device.
In addition, there exists another type of an image-forming-device management system, in which an image-forming device having a function (communication control means) as a data communication device can be connected to a central management device installed in a service center, by use of a communication line, and the central management device executes remote management of the image-forming device through the communication line.
In such an image-forming-device management system, the image-forming device transmits data related to the image-forming device to the central management device, by calling out spontaneously and periodically, for instance, on a fixed date and time of every month, or by responding to a call signal that corresponds to a call out made by the central management device, and is received through the communication line.
On the other hand, one of recent image-forming devices such as copy machines or facsimile devices has an energy-saving function to stop supplying power from a power source to a part that consumes much electricity, by setting an energy-saving mode, for the purpose of saving energy or setting consumed energy low if a state in which the image-forming device is not used for a certain period, or if a fixed key operation on an operation display unit is performed.
A facsimile (FAX) device having the above-described energy-saving function is shown in FIG. 1, for example. FIG. 1 is a block diagram showing a structure of a related-art facsimile device that has an energy-saving function.
This facsimile device includes a CIG4 401, an NCU (Network Control Unit) 402, an FCU (Facsimile Control Unit) 403, a scanner 404, a plotter 405 and a main control unit 406. In addition, the facsimile device includes an operation display unit, a main power source and a sub power source, which are not shown in the figures.
The CIG4 401 is a unit for a G4 (Group-4 type) of a facsimile device. The NCU 402 is a network control unit that connects or disconnects lines, and detects connected lines. The FCU 403 is a facsimile control unit that controls communication with an external facsimile device, and includes a CPU (Central Processing Unit) 411, a ROM (Read Only Memory) 412, a RAM (Random Access Memory) 413, an RTC (Real Time Clock) 414, a UART (Universal Asynchronous Receiver/Transmitter) 415, a VIF (Video Interface) 416, a BUSCNT (Bus Control) 417, a DCR 418, a memory 419, a PORT 420, a FAX modem 421, a COMCNT (Communication Control) 422, an AFE (Analog Front End) 423, a DTMF 424, and the like.
The CPU 411 is a central processing unit that controls the FCU 403 entirely. The ROM 412 is a read only memory that stores every type of fixed data including a control program used by the CPU 411. The RAM 413 is a memory temporarily storing data, and is a work memory used by the CPU 411 for processing data, for instance. The RTC 414 is a real-time-clock circuit that includes a timer function generating a current time. The current time is known by the CPU 411 reading the current time generated by the RTC 414.
The UART 415 is a serial communication unit that functions as an interface exchanging a control signal with the main control unit 406. The VIF 416 is a video interface that exchanges image data (image information) with the main control unit 406. The BUSCNT 417 is a bus control circuit that connects or disconnects buses, and substitutes a bit on a bus with another bit on the other bus. The DCR 418 is a compression/decompression circuit that compresses or decompresses the image data. The memory 419 stores the image data. The PORT 420 is an I/O (Input/Output) port that controls input and output of each signal by following an instruction from the CPU 411.
The FAX modem 421 modulates or demodulates image data for a facsimile operation, which is received or to be transmitted. The COMCNT 422 is a communication control circuit that controls input and output of each signal by following an instruction from the CPU 411. In addition, the COMCNT 422 detects or receives a call signal (a ringer signal) corresponding to a call out made by an external facsimile device, and notifies the CPU 411 about the call signal, if the call signal is transmitted from a communication line to the facsimile device shown in FIG. 1. The AFE 423 is an analog front end (an analog signal control circuit) that amplifies and filters a signal from the communication line (a telephone line). The DTMF 424 detects a DTMF signal, for example, a combination code of “*#0#” transmitted from an external device to the facsimile device shown in FIG. 1 through the communication line.
The scanner 404 reads a document image. The plotter 405 forms or prints an image on a sheet of paper, based on image data read by the scanner 404, or image data received by the FCU 403 or the like from an external facsimile device. The main control unit 406 controls the FCU 403, the scanner 404 and the plotter 405 all together.
The facsimile device structured as described above stops supplying power to a display device on the operation display unit, the scanner 404 and the plotter 405 including a fixing roller inside a fixing unit, whose electricity consumption amounts are large, by turning the main power source off in a case in which the energy-saving mode is set. Additionally, the facsimile device continues supplying power from the sub power source to the FCU 403, the CIG4 401 and the NCU 402 that compose a control unit.
In a case in which the COMCNT 422 of the FCU 403 receives the call signal (the ringer signal) that corresponds to the call out made by the external facsimile device, and is transmitted from the communication line through the NCU 402 during the energy-saving mode, the COMCNT 422 notifies the CPU 411 about the received call signal. Subsequently, the CPU 411 having received the notification from the COMCNT 422 supplies the power to the entire facsimile device by turning the main power source on. In addition, the CPU 411 outputs image data to the plotter 405, and makes the plotter 405 form an image or print the image on a sheet of paper, in a case in which the facsimile device receives the image data from the communication line continuously after the reception of the call signal.
This facsimile device also stops supplying the power to the display unit on the operation display unit, the scanner 404 and the plotter 405 by turning the main power source off, in a case in which the energy-saving mode is set while a data-transmission time is set (or a time-specified transmission mode is set). However, the facsimile device continues supplying the power from the sub power source to the FCU 403, the CIG4 401 and the NCU 402. In a case in which the CPU 411 determines that the current time generated by the RTC 414 and a predetermined data-transmission time match with each other by comparing the current time and the data-transmission time during the energy-saving mode, the CPU 411 transmits document image data that is read by the scanner 404 and is stored in the memory 419 in advance, to a predetermined address by using the FAX modem 421, the COMCNT 422 and the NCU 402.
However, the initially described image-forming-device management system using the data communication device among the above related-art image-forming-device management systems has the following problems.
The data communication device used in the initially described image-forming-device management system keeps turning its main power source on at all times, thereby being supplied with the power from the main power source constantly, so that the data communication device can transmit the data related to the image-forming device to the central management device at any time. Consequently, the image-forming-device management system wastes electricity when the data communication device is not transmitting the data to the central management device.
Additionally, the image-forming device used in the initially described image-forming-device management system cannot respond to a data-transmission request transmitted from the data communication device, in a case in which the image-forming device cuts power supply from its main power source to the entire image-forming-device by turning the main power source off according to a turned-off main switch, or in a case in which the image-forming device cuts the power supply from the main power source to the entire image-forming device by turning the main power source off in accordance with continuation of an used state for a certain period, in order to achieve energy saving.
Further, if the main power source of the image-forming device is turned off, the data communication device cannot obtain the data related to the image-forming device therefrom by calling out spontaneously at a fixed time or by receiving the call signal (the data-transmission requesting signal) from the central management device, and, thus, cannot transmit the data to the central management device.
On the other hand, the later described image-forming-device management system whose image-forming device includes the communication control means has the following problems.
The entire image-forming device that has the communication control unit, and is used in the later described image-forming-device management system is supplied with the power from the main power source at all times, by turning the main power source on, so that the image-forming device can transmit the data about itself to the central management device. Consequently, the image-forming-device management system wastes electricity when the image-forming device is not transmitting the data to the central management device.
In addition, the image-forming device cannot respond to the call signal transmitted from the central management device, in a case in which the image-forming device cuts power supply from its main power source to the entire image-forming device by turning the main power source off according to a turned-off main switch, or in a case in which the image-forming device cuts the power supply from the main power source to the entire image-forming device by turning the main power source off in accordance with continuation of an used state for a certain period, in order to achieve energy saving.
Accordingly, usage of a technology related to the related-art facsimile device shown in FIG. 1 may be applied to the image-forming device and the data communication device used in each image-forming-device management system described above.
Such a facsimile device stops supplying power to parts consuming much energy, such as the display unit on the operation display unit not shown in the figures, the scanner 404 and the plotter 405, by turning the main power source off when the energy-saving mode is set. However, the facsimile device needs to continue supplying the power from the sub power source to the FCU 403, the CIG4 401 and the NCU 402 composing the control unit, so that the facsimile device can transmit or receive image data during the energy-saving mode. Thus, the facsimile device certainly consumes the electricity for continuing the control unit powered on.